Now when we need to learn something all we have to do is boot up a computer and connect to the internet.
A search engine is an information retrieval system designed to help locate information from a huge database of 10s of thousands of interlinked servers(Google especially). Most people are familiar with Google, yahoo, and ask.com. Search engines work when a user types a keyword into the little box. Once the user types in the word the search engine scans all its files. It then provides the user with a page that is full of options, generally twenty. The user scans the list of options and then opens the one that sounds like it best suits their needs. Search engines use something called search engine optimization to determine the ranking of each web address.
Search engine optimization is the art and science of making web pages attractive to the search engines. The more a website appeals to the search engine the higher it will be ranked.
Crawler or Search engine worker bees do not look at images but instead read the "Alt" tags attached to every image on your website. These worker bees are essential for the search engines, they do multiple type of jobs like analyzing the keyword density/frequency of your content, then look at the title of your page and try to match both of them.
Of course SEO is not an exact science, some people will tell you one thing while others will go against it, we can all agree that Backlinks, webpage titles and keywords densite are the most important ranking factors.
The more backlinks from higher PR sites you get, the higher your PR will be, som say that the higher your PR is, the higher your search engine rank will be, many do no agree with this.
The location of the key words is as important as the frequency.
The first place a search engine looks for keywords is in the title. Web designers should include a keyword in their HTML title tag. Web designers should also make sure that keywords are included near the top of the page. Search engines operate under the assumption that the web designers will want to make any important information obvious right away.
Spamdexing is a term used to describe a webpage that uses a certain word hundreds of times in an attempt to propel their webpage to the top of search engines rankings. Most search engines use a variety of methods, including customer complaints, to penalize websites that use spamming methods. Very few internet search engines rely solely on keywords to determine website ranking. Many search engines also use something called "off the page" ranking criteria. Off the page ranking criteria are ranking criteria's that webmasters cannot easily influence. Two methods of off the page search engine optimization are link analysis and click through measurement.
A lot of people are trying to use complex method to rank higher, like creating forum accounts with a backlink, auto commenting on high PR blogs, submit multiple times per month their RSS feeds, all these methods do work well, all you need now are the right tools for the job.